VANCOUVER, B.C. The epidermal growth factor receptor inhibitor cetuximab alone has been found to produce complete response in patients with advanced cutaneous squamous cell carcinoma.
"To date, there have been no trials using the epidermal growth factor receptor inhibitors for treatment of patients with cutaneous squamous cell carcinoma," said Dr. Matthew E. Halpern at the annual meeting of the American College of Mohs Surgery. A previous trial found that cetuximab (Erbitux) plus radiation was efficacious for treating locally advanced squamous cell carcinoma (SCC) of the head and neck (N. Engl. J. Med. 2006;354:567-78).
Study patients had advanced SCC of the back, scalp, temple, and chest, according to Dr. Halpern, a dermatologic surgeon at New York-Presbyterian Medical Center. Two patients had in-transit metastasis alone, one had both in-transit and axillary metastases, and one had pulmonary metastases. Their treatment consisted of weekly infusions of cetuximab, with a total of four infusions planned.
Two patients had a complete clinical response to cetuximab (Erbitux), Dr. Halpern reported. "Really, like magic, the in-transit metastasis absolutely melted before our eyes," he said, describing one of the patients. Another patient, who received only half of the planned number of infusions because of comorbidities, had a partial response. The remaining patient had merely a limited response.
"As you might expect, side effects of this class of medications are largely cutaneous," Dr. Halpern noted, explaining that patients might develop a characteristic acneiform rash, paronychial inflammation, xerosis, pruritus, and trichomegaly. The study's two complete responders developed a severe rash, and the partial responder developed a moderate rash, while the nonresponder did not develop any rash at all. "Interestingly, even though this is a very small series of patients, patient response seemed to correlate with the severity of acneiform eruption," he observed. "It seemed to be a surrogate marker for therapeutic response."
One of the patients with a complete response was alive at 6 months after treatment, while the other died 7 months afterward from a primary lung cancer. The patient with a partial response died 4 months after treatment from chronic rejection of a lung transplant and had additional metastases at that time. The patient who had a minimal response died 4 months after treatment from brain metastases.
The study had limited follow-up related to the recent treatments patients had received and their comorbidities, Dr. Halpern conceded. Nonetheless, he said, "cetuximab has potential benefit for patients with metastatic cutaneous squamous cell carcinoma and is extremely well tolerated in our hands, with minimal side effects, some of which may be predictive of therapeutic benefit."
Dr. Halpern reported that he had no conflicts of interest in association with the study.
'The severity of acneiform eruption … seemed to be a surrogate marker for therapeutic response.' DR. HALPERN
Biopsy of this nodule revealed infiltrating SCC without epidermal involvement.
The patient's in-transit metastasis and axillary metastases cleared after the third cetuximab infusion. The acneiform rash is characteristic of this drug class. Photos courtesy Dr. Matthew E. Halpern